The present invention relates to a small-sized fluorescent X-ray film thickness monitor to be installed in a manufacturing line in order to monitor for nickel electroless plating film thickness on aluminum substrate of a hard disc.
As hard disc density increases, there is a growing problem of base flatness or evenness in opposite surface film thickness of substrate electroless nickel plating. It is becoming important to monitor electroless nickel plating film thickness immediately after electroless nickel plating or before or after polishing in a manufacturing line. Conventionally, sampling inspections have been conducted with an off-line fluorescent X-ray gauge.
The conventional sampling inspection has involved a problem in that occurrence of a product rejection results in a rejection on a lot basis thus raising a rejection rate under recent severe criteria. Due to this, there has been a necessity to adjust working conditions to decrease the rate of rejection by conducting an in-line re-measurement for immediate feedback. In installing a fluorescent X-ray film thickness gauge in the production line of a coated part, there has been a dimensional problem of an X-ray generating system as well as a problem of fluttering of measurement samples. Therefore, it is an object of the present invention to provide a fluorescent X-ray monitor that is small in size and excellent in characteristic for in-line installation in the production line of a coated part for measuring the film thickness of the coating applied to the part.